The inventive subject matter relates to power supply apparatus and methods, more particularly, to uninterruptible power supply systems and methods of operating the same.
Uninterruptible power supply (UPS) systems are commonly used to provide power supply redundancy and quality in a variety of different applications, such as in data centers medical centers and industrial facilities. Typically, UPS systems may be used to provide power from a backup source (e.g., battery, flywheel, fuel cell, etc.) to maintain operation of equipment in the event of the failure of a primary utility power supply.
In some installations, respective UPSs may be used to provide uninterruptible power to respective groups of equipment. Such an arrangement typically involves sizing the respective UPSs based on the power requirements of the equipment that they serve. UPSs may also be used in output-paralleled arrangements in which multiple UPS may share a load and redundant arrangements in which multiple UPSs are configured to back up one another in the event of a UPS failure. Examples of UPS arrangements supporting redundancy and load sharing are described in U.S. Pat. No. 7,459,803 to Mosman and U.S. Pat. No. 8,850,237 to Familiant et al.